Manufacture of acid ammonium phosphate.



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WILHELM WOLLENWEBEB,

0F BOGHUM, GERMANY.

MANUFACTURE OF ACID AMMOITITTM PHOSPHATE.

No Drawing.

' To all whom it may concern:

Be it known that I, WrLHnLM Woman:- wnnnn, a subject of the Emperor of Gerresiding at Bochum, Westphalia, Germany Empire, have invented certain new and useful Improvements in the Manufacture of Acid Ammonium Phosphate; and I do hereby declare the following to be a full, clear, and exact description of the-invention, such as will enable others skilled in the art to which it appertains to make and use the same. a

This invention relates to a process for the manufacture of acid ammonium-phosphate.

The manufacture of acid ammoniumphosphate meets with great difliculties when technically workedizligon' the one hand it is not easy to recognize" 'the end of the reaction and to, prevent the absorption of greater quantities of ammoniabeyontl the formula (NH- H 1 0 which produces unstable combinations. v On the other hand it is expensive and gives much trouble to remove the adhering water. These faults are avoided in the present invention by conveying ammonia-vapor into phosphoric acid until the solution shows a weak alkaline reaction. For this purpose, impure gases containing ammonia, as coke-furnace-gas, .Mond-gas, and even synthetic ammonia maybe used. The process can be accomplished periodically or continuously.

The treatment is or closed saturation-boxes, out salt that has formed is sucked working is done continuously.

In order to counteract the great heat that which heat dequick separation of the solid salt, the solutioniium most/successful in open of which the out when the lays the it is practical to cool down ingreaction.

The mother-liquor is removed from the salt mass by suction or by centrifugalization. It is then'mixed with a strong phgsphoric acid and returned into the cycle 0 operations If hosphoric acid of a definite concentration'is used, one obtains withthis process directlysolid salt capable of being shipped without further'treatment, which means the i sa ing of the cost of'eva oration. The most tained farorable working con 'tions are ob specification of Letters Patent.

Application filed October 19, 1915.

.by usin monia to it.

.suitable heating coil.

an air current, and

, ture at about 110 Patented Dec. 19, 1916.

Serial No. 56,802.

phosphoric b t t 32 acid of 30 B., that IS roug up 0 B., by supplying am- A greater yield is quickly attained if the acid that is to be treated is first warmed, and if without exceeding a certain reaction temperature,.all efforts are directed toward obtaining a density as high as possible. The

'most'appropriate temperature of reaction is 110 C. This process is carried out in detail as follows: The phosphoric acid, the concentration of which is about 30 B., is first heated up to 80-90 (1., for instance by a The acid is subjected to the action of the ammonia until the mass has a density of 3738 B., the temperature being kept at 110 'C. i To .do this under all conditions, it may be necessary to cool during" the course of the reaction. The end of the reaction is always indicated by a slight alkaline reaction. After this, the contentsof the reaction chamber are removed,

the mass is cooled, for instance by means of,

finally subjected to contrifugalization. The mother-liquor is re turned was reaction chamber and used for further reactions.

I claim- A v 1. In the rocess for the manufacture of acid ammonium-phosphate, the step which comprises conveying ammonia into phos--' phoric acid until a weak alkaline reaction results, and maintainin the reaction tempcrature at about 110 V 2. In the process for the manufacture of acid ammonium-phosphate, the step which comprises conducting ammonia into phosphoric acid of 30 B., until a minimum 32 B., are reached.

3. The process for the manufacture of acid ammonium-phosphate which comprises warming 30 B., phosphoric acid to 80'-90 (3;, conducting amm'onla into the same until the solution has a concentration of 37-38 B., andmaintainin the ,reaction tempera- 4. The process for themanufacture of acid ammoninm phosphate, which comprises warmin 30 B.,phosph'oric-acid to 8090 C. ,'L=subeotingithe,acid to the action of the "ammonia @until centration of S7 38 the solution has a con- B., and is slightly alkaline, maintaining the reaction temperature at about 110 (1., separating the salt- Inuss from the mother-hquor, mixing the separated liquor with a, strong phosphoric acid and returning the mixture into the cycle of operations,

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

WILIIELM WOLLENWEBER. [n 8-] \Vitnesses ALBERT Nurnn,

l RANGES NUFER. 

